The DOCK program uses geometric methods to find possible protein-ligand and protein-protein orientations. I am interested in developing geometric descriptors which can be used by the DOCK program to explore and evaluate possible orientations. My current method uses the solid angle of the surface to find concave and convex regions. Graphical programs such as MIDASPlus are used to examine the surfaces and project the solid angle value onto the surface by varying the color of the surface.